Recovery of Myocardial Perfusion in Acute Myocardial Infarction After Successful Balloon Angioplasty and Stent Placement in the Infarct-Related Coronary Artery

Objectives. This study sought to investigate changes in myocardial perfusion after direct percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (MI).Background. After initially successful recanalization of the infarct-related artery, coronary perfusion may deteriorate as a result of reocclusion, distal embolization of platelet aggregates formed at the dilated plaque or microvascular reperfusion injury. This change could offset the benefit from early intervention.Methods. The study included 19 patients in whom the infarct-related artery was successfully recanalized by PTCA with Palmaz-Schatz stent placement within 24 h after the onset of pain. Basal and papaverine-induced coronary blood flow were assessed by Doppler flow velocity measurements and quantitative coronary angiography. In addition, basal and adenosine-induced myocardial blood flow were measured by nitrogen-13 ammonia positron emission tomography (PET).Results. Immediately after completion of the intervention, the average coronary flow reserve (CR) in the recanalized vessel was 1.56 ± 0.51; it increased to 2.04 ± 0.65 at 1 h (p = 0.013) and to 2.66 ± 0.72 at 2 weeks after reperfusion (p = 0.008, n = 16). PET studies in 12 patients revealed that perfusion defect size and CR in the infarct region (2.19 ± 0.89 vs. 2.33 ± 0.86) did not change significantly between day 2 after recanalization and 2 weeks. However, we found significant (p < 0.03) increases in basal (by 26%) and adenosine-induced (by 40%) blood flow in the infarct region.Conclusions. Despite the persistence of a perfusion defect after successful recanalization of the occluded artery in acute MI, CR of the infarct region improves in most patients within 1 h and further improves within 2 weeks.     

Safety and Efficacy of Angiographic Guided Elective Palmaz-Schatz Stent Implantation Without Coumadin: Comparison of Stent Implantation and Angioplasty

This study was designed to evaluate the safety and efficacy of routine high-pressure Palmaz-Schatz coronary stenting in patients with symptomatic coronary heart disease with only angiographic guidance without coumadin for poststenting treatment. Intracoronary stenting reduces restenosis rate after coronary angioplasty. High pressure stent deployment with intravascular ultrasound guidance reduces the incidence of stent thrombosis, despite reduction of anticoagulation. However, the feasibility of routine stent implantation with only angiographic guidance and without coumadin for poststenting treatment has not yet been determined. Patients undergoing coronary angioplasty for symptomatic coronary heart disease received stent implantation for abrupt or threatening vessel occlusion, vessel dissection without compromised antegrade blood flow (but at high risk for subacute occlusion and early restenosis), unsatisfactory angioplasty result with > 30% residual stenosis, and elective stent implantation in de novo lesions, restenotic lesions, and lesions in bypass grafts. Quantitative coronary analysis was performed before the procedure, immediately after, and at follow-up 6 ± 1 (SD) months later. This patient group was matched for clinical and angiographic characteristics with those patients who underwent balloon angioplasty during the same period. Patients who underwent coronary stenting had larger net gain (1.95 ± 1.0 vs 1.42 ± 0.9; P < 0.001) resulting in a larger minimal luminal diameter (2.48 ± 1.19 vs 1.78 ± 1.01; P < 0.001) at follow-up as compared with balloon angioplasty. Restenosis, defined as > 50% diameter stenosis at follow-up, occurred in 35.0% in the PTCA group and in 16.1% in the stent group (P < 0.001). Subacute stent thrombosis occured in one patient (0.8%) due to angiographically evident suboptimal stent expansion. Routine coronary high pressure Palmaz-Schatz stenting with angiographie guidance without coumadin for poststenting treatment represents a safe and effective option in patients with symptomatic coronary heart disease without increasing the incidence of (sub)acute stent thrombosis.     

Stent Placement Versus Angioplasty Improves Patency of Arteriovenous Grafts and Blood Flow of Arteriovenous Fistulae

Background: While endovascular stent placement is the standard of care in most percutaneous coronary and peripheral artery intervention, its role in the salvage of thrombosed and stenotic hemodialysis access remains controversial.Design, Setting, Participants, and Measurements: We compared the effects of stent versus angioplasty on primary patency rates in the treatment of stenotic arteriovenous fistulae (AVF) and arteriovenous grafts (AVGs). Moreover, we compared access flow (Qa) and urea reduction ratio (URR) between the two groups as a metric of the effect of stent placement versus angioplasty on dialysis delivery.Results: Cox regression analysis revealed that the primary assisted AVG patency was significantly longer for the stent group compared with angioplasty, with a median survival of 138 versus 61 d, respectively (aHR = 0.17; 95% confidence interval, 0.07 to 0.39; P < 0.001). The primary AVG patency for stent versus angioplasty was 91% versus 80% at 30 d, 69% versus 24% at 90 d, and 25% versus 3% at 180 d, respectively. The primary assisted AVF patency did not differ significantly between the stent and angioplasty groups. In patients dialyzing via AVF, multiple regression analysis revealed that stent placement was associated with improved after intervention peak Qa, 1627.50 ml/min versus 911.00 ml/min (β = 0.494; P = 0.008), change in Qa from before to after intervention, 643.54 ml/min versus 195.35 ml/min (β = 0.464; P = 0.012), and change in URR from before to after intervention, 5.85% versus 0.733% (β = 0.389; P = 0.039).Conclusions: Our results suggest that stent placement is associated with improved AVG primary assisted patency and improved AVF blood flow, which may significantly impact on dialysis adequacy.Despite a multitude of recent theoretical advances, emerging clinical data, and well-articulated guidelines, vascular access remains the Achilles heel of hemodialysis (1). The most common cause of dysfunction or loss of the arteriovenous access is thrombosis in the low flow state (2). The patency of arteriovenous grafts (AVGs) and arteriovenous fistulae (AVF) is compromised mainly by intimal hyperplastic lesions, which usually develop in areas of turbulent flow. These lesions tend to occur at sites of artery-to-vein or graft-to-vein anastomoses (3–5). Numerous studies have demonstrated the effectiveness of balloon angioplasty in the treatment of stenotic lesions, but this procedure is associated with a high rate of recurrent stenosis. Early studies of angioplasty reported 6-mo primary patency rates of only 31% to 64% (5–7).The limited success of intervention via angioplasty contributes to the inordinate amount of healthcare costs associated with end-stage renal disease and vascular access. The estimated total per person per year costs for hemodialysis access (grafts and fistulae) is greater than $9000, which is approximately a 40% increase from 1999 (8), at which time the annual cost of access related morbidity in the United States was estimated to be more than $1 billion (9). A large proportion of these costs encompass the morbidity associated with outpatient and inpatient procedures to salvage failed and failing access (8).Although endovascular stent placement is the standard of care in most percutaneous coronary and peripheral artery disease interventions, its role in the salvage of thrombosed and stenotic hemodialysis access remains controversial. Percutaneous transluminal angioplasty (PTA) of hemodialysis access has been described since the 1980s (10,11). It offers an alternative to surgical revision (jump grafts, graft interposition, venous patch angioplasty, and open thrombectomy) without the considerable morbidity, length of stay, and costs typically associated with surgery (12,13). Endovascular stent placement, on the other hand, has been used in the management of hemodialysis access stenosis since 1988 (14,15). Stents have been used predominantly as a salvage to failed angioplasty (venous rupture, elastic recoil, rapidly recurrent stenosis after PTA, or residual stenosis >30%) or as adjunctive therapy. Multiple studies have compared stent versus angioplasty in terms of access patency with mixed results (16–21). In these studies, multiple confounders, such as a wide variety of stent types, the nature and locations of the stenotic lesions, the access configuration, the blood flow measurements, and the case mix, prevent the clinician from drawing definitive conclusions regarding the use of stent versus angioplasty (22). A recent observational cohort study by Maya and Allon addressed some of the aforementioned limitations and demonstrated improved primary and secondary graft patency after thrombectomy of AVGs (23).The role of stent placement in the treatment of stenotic lesions (those not associated with thrombosis per se) in AVGs and AVF remains poorly defined. The objectives of our study are twofold: 1) to compare the effects of stent versus angioplasty on patency rates in the treatment of stenotic AVF and AVGs, controlling for age, gender, location of lesion, and stent type; and 2) to compare access flow (Qa) and urea reduction ratio (URR) between the two groups as a metric of the effect of stent placement versus angioplasty on dialysis delivery.     

Coronary Drug-Eluting Stent Infection Complicated by Coronary Artery Aneurysm and Purulent Pericarditis: Complete Resolution Without Surgery

Coronary stent infection is considered to be a rare but catastrophic complication of percutaneous coronary intervention. In this report, we present a 72-year-old man who developed a coronary stent infection complicated by coronary aneurysm and purulent pericarditis. Coronary artery aneurysm resolved over a period of 8 months following the successful management of infection with intensive antibiotic therapy alone. This case suggests that conservative therapy can be a therapeutic option in patients with high operative risks.     

Interaction of Intraluminal Tissue and Coronary Sinus Lead Stabilized with Stent Placement

Intraluminal Interaction of Tissue and Stented CS Lead . Introduction: The aim of our investigation was to examine the intraluminal interaction of the vascular tissue and the implanted coronary sinus lead stabilized with stent on two human hearts removed before transplantation. Methods and results: The coronary sinus lumen was sectioned under operational microscope and opened carefully. The leads and stents were found separately positioned beside each other completely covered by an intact intimal tissue layer. No sign of occluding proliferative tissue was observed. Conclusion: Stent fixation technique and extraction of the CS lead in our cases did not have any particular damaging effect on the vascular system. (J Cardiovasc Electrophysiol, Vol. 24, pp. 468‐470, April 2013)     

The New ACS Multilink Coronary Stent: Single Center Experience in 103 Consecutive Patients With and Without Oral Anticoagulation

Since the introduction of this stent, anticoagulant regimens have changed from an aggressive protocol (aspirin, heparin, and warfarin) to a simplifed regimen (aspirin and ticlopidine). In this study our experience with this stent is reviewed, and acute and chronic outcomes with the two anticoagulant protocols are compared. All patients undergoing ACS Multilink stent implantation between July 1993 and June 1996 were included. The clinical and angiographic characteristics were documented and outcomes recorded. The two anticoagulant groups were compared: 103 patients (94 males, age range 41–80 years, mean 59) received 124 stents: 68% had Canadian Cardiac Society (CCS) grade III or IV angina prior to the procedure; and 73% underwent bail-out stenting. High pressure inflations (> 14 a) were used in 40% of cases. Eighty-four (85%) received aspirin and ticlopidine only. The initial success rate was 99%. Two patients underwent emergency surgery. There were no deaths and no cases of subacute stent thrombosis. Clinical follow-up is available on 66 patients (mean 190 days). Of these, 56 patients (54%) are in CCS grade 0 or 1. One patient has required surgical revascularization. There is one case of documented restenosis within the stented segment .     

Complete Myocardial Revascularization by Single Session Triple Vessel Percutaneous Coronary Angioplasty and Provisional Stenting

Background: Although availability of stents has made percutaneous transluminal coronary angioplasty (PTCA) safer, single vessel angioplasty still represents 90% of procedures performed today. We report our initial experience with single session triple vessel angioplasty, using stents as needed to improve suboptimal balloon results. Patients: Fourteen patients (12 men, 85%), aged 67 ± 19 years were treated. All had triple vessel disease and angina. Mean left ventricular ejection fraction was 61%± 8%. Results: PTCA was attempted in all three coronaries or one of their major branches during the same procedure. Seventeen target lesions were in the left anterior descending coronary artery, 2 in a diagonal branch, 11 in the left circumflex, 2 in a marginal branch, 13 in the right coronary artery, 3 in the posterior descending, and 1 a saphenous vein graft. PTCA of 3.5 ± 0.7 sites/procedure was attempted. The success rate was 13 (93%) of 14 patients and 47 (96%) of 49 lesions. Thirty-four (69%) lesions were treated by implantation of one or several stents, and 10 (71%) of 14 patients received at least one stent. Hospital stay duration was 4 ± 2 days. One patient required repeat PTCA to treat subacute stent thrombosis 2 days after the procedure (creatine kinase [CK] peak < 2 times upper limit of normal). There were no in-hospital deaths, Q-wave infarction, or need for coronary artery bypass grafting (CABC). After a median follow-up period of 24 months (range 3–102), one (7%) patient had died of a noncardiac cause, three (21 %) had required repeat PTCA for restenosis in previously dilated lesions, and none had suffered a myocardial infarction. At follow-up, the median angina class was I (range I-II). Conclusion: For selected patients with three vessel disease, complete revascularization by single session PTCA and provisional stenting as needed is feasible, and is associated with a low rate of short- and long-term complications when successfully performed.     

The Clinical and Angiograghic Outcome of 190 Cases after Stent Placement in Small Coronary Vessels

Objectives To invest the success procedure, immediate outcome after procedure, the rate of main adverse cardiac events after procedure and restenosis after stent placement in small coronary vessels. Methods 290 patients with selected or emergency stent implantation in small vessels from April, 1997 to March,2002. Total 299 vessels,304 lesions and 316 stents were statisted. The successs rate of procedure, immediate outcome after procedure, the rate of main adverse cardiac events after procedure and restenosis after stent placement in small coronary vessels were assessed. The patients were followed up 1 month to 4 years. Re-catheter angiography were done in 122/290 patients. Results The narrow rate of lesion dropped from 89% ± 12% before procedure to 5% ±5% after procedure (diameter). 202 patients were followed up 1 month (69.7%). 197/202 cases were survival. 5/202 cases died in 3hrs to 7days. 2/5 cases died of persistent hypotension after procedure. 1/5 case died of acute left heart failure. 2/5 cases     

Covered-Stent Treatment of Coronary Aneurysm after Drug-Eluting Stent Placement: Case Report and Literature Review

Most commonly, coronary artery aneurysms are secondary to atherosclerosis, but cases have been reported in patients who have vasculitis or tissue disorders, and in patients who have undergone interventional procedures. However, over the past few years, an increasing number of cases of coronary artery aneurysms after drug-eluting stent implantation have been reported. The exact mechanism is unknown. Experimental animal studies have shown that both the active drug and the polymer coating, under certain circumstances, might cause progressive luminal dilation, positive vascular remodeling, and aneurysmal formation. Complications like rupture, thrombosis, embolization, myocardial infarction, and even sudden death have been reported. Treatment options vary from aggressive surgical ligation of the aneurysm, in union with distal bypass surgery, to percutaneous implantation of a covered stent or conservative medical management with continued antiplatelet therapy. Currently, there is no consensus on an ideal approach to treating coronary artery aneurysm after drug-eluting stent implantation. Polytetrafluoroethylene-covered stents, easy and rapid to deploy, have emerged as a newer option. We report a case of coronary artery aneurysm at the site of a previous drug-eluting stent. The lesion was successfully treated with a polytetrafluoroethylene-covered stent.Key words: Blood vessel prosthesis, coronary aneurysm/etiology/therapy, coronary disease/therapy, covered stents, dilatation, pathologic, drug delivery systems/adverse effects, drug-eluting stents/adverse effects, polytetrafluoroethylene, postoperative complications, sirolimus/administration & dosage, stents/adverse effectsAneurysmal dilation of the coronary arteries was first described by Bougon in 1812.¹ Most commonly, coronary artery aneurysms are secondary to atherosclerosis,² but cases have been reported in patients who have vasculitis (Kawasaki syndrome,³ for example) or tissue disorders (Ehlers-Danlos⁴ or Marfan syndrome,⁵ for example), and in patients who have undergone interventional procedures.^6,7 Over the past few years, an increasing number of case reports have described a growing incidence of coronary artery aneurysms after drug-eluting stent (DES) implantation.^8–11 Since 2003, when the U.S. Food and Drug Administration approved the 1st such stent, DESs have unequivocally demonstrated their superiority to bare-metal stents in regard to in-stent restenosis.^9–12 Nevertheless, safety concerns brought up from time to time—especially regarding the increased risk of late stent thrombosis¹³—have raised questions about the long-term safety of DES implantations.The exact mechanism of coronary artery aneurysmal formation after DES placement is unknown. Complications such as rupture,¹⁴ thrombosis,¹⁵ distal embolization,¹⁶ myocardial infarction,¹⁷ and even sudden death¹⁸ have been reported. Here we report a case of coronary artery aneurysm at the site of DES implantation, which we successfully treated with a polytetrafluoroethylene (PTFE)-covered stent. In addition, we present a review of the literature on the use of PTFE-covered stents in the repair of coronary artery aneurysms that have formed at the site of DES implantation.     

单光子发射型计算机断层心肌灌注显像对经皮冠状动脉腔内成形术的近期疗效评估

目的：探讨单光子发射型计算机断层摄影术（ＳＰＥＣＴ）心肌灌注显像在评估经皮冠状动脉腔内成形术（ＰＴＣＡ）治疗冠心病效果中的作用。方法：通过运动—静息心肌灌注显像，观察ＰＴＣＡ前后患者运动试验结果、心肌各心室壁节段放射性异常积分及靶心图缺损范围的变化。结果：ＰＴＣＡ后患者运动耐量增加；放射性异常积分及靶心图缺损范围明显缩小，说明近期缺血明显改善。８例多支病变患者中，有６例仅进行部分血运重建，心肌灌注显像示缺血严重、范围广的心肌节段，其相关血管多为“罪犯”（ｃｕｌｐｒｉｔ）血管。结论：ＳＰＥＣＴ心肌灌注显像对ＰＴＣＡ近期疗效评估具有较高的实用价值，并可为ＰＴＣＡ前判断需要扩张的关键性病变血管提供帮助。     

三磷酸腺苷负荷单光子发射型计算机断层摄影术心肌灌注显像对经皮冠状动脉腔内成形术的疗效评价

目的探讨三磷酸腺苷(ATP)负荷单光子发射型计算机断层摄影术(SPECT)心肌灌注显像在评价冠心病患者经皮冠状动脉腔内成形术(PTCA)疗效中的作用.方法冠心病患者62例,依临床特点及SPECT显像分为2组,单纯心肌缺血组22例及心肌梗塞伴缺血组40例.ATP按0.28mg/(kg@min)的速度匀速泵入共5min行SPECT检查,观察PTCA前后心肌各心室壁节段放射性异常积分及靶心图缺损范围的变化.结果ATP负荷SPECT检查副作用轻、消失快,耐受性好;PTCA术后放射性异常积分降低及靶心图范围缩小说明近期缺血改善明显;术前心肌灌注显像示缺血严重、范围广的心室节段,其相关血管多为"罪犯”血管;PTCA术后3～6个月,10例患者发现再缺血,经冠状动脉造影证实有再狭窄发生.结论ATP负荷SPECT为评价冠心病患者PTCA疗效及探测术后再狭窄的安全而准确的方法并有助于术前选择病变血管.